Franz Seiser, VP Core Network and Services, Deutsche Telekom, Germany, is speaking on Day One of the LTE Voice Summit, taking place on October 1st-2nd at the Hilton Paddington, London. Ahead of the show we speak to him why operators have been slow to implement IMS and the benefits the services running on it will bring.

At the LTE Voice conference you’re addressing the issue of slow IMS deployment. Do you think it’s symptomatic of the struggle that many telecoms operators are having moving to IP-based thinking?

The fact is that IMS deployments are rather slow. From a technology perspective this is due the extremely high complexity of these deployments. IMS complexity drivers can be split up into six different groups and IMS’ inherent complexities is one of these groups. The mismatch of traditional telco design approaches with IP technologies another one. I will give an overview on all six categories during my talk at the LTE Voice summit.

Why would IMS have an impact on LTE roaming capabilities?

By design, LTE is a fully data-centric network with no intrinsic support for the classical circuit-switched based services voice and SMS. When roaming, LTE provides data roaming capabilities only. If IMS based services are to work in roaming scenarios as well, some kind of roaming functionality will be required on top.

What is the most important technology that will affect LTE in the next 12 months?

From a core network perspective we expect to finally see initial launch of VoLTE (but without roaming) as well as LTE data roaming to happen across the industry. A bit further out, probably over the next 24-36 months, Network Function Virtualisation (NFV) will start to play an important role.

Once implemented, do you think that IMS-based services will help retain customers and raise ARPU?

Raising ARPU from initial IMS based services like RCSe/Joyn and VoLTE may prove to be difficult, but these services are definitely intended to help increase “customer stickiness”. They are key building blocks of our all-IP strategy.

How will consumers benefit from the move to VoLTE?

Customers can expect persistent high quality of voice calls with ubiquitous reach (compared to OTT offerings) as well as shorter call-setup times and better audio quality (compared to legacy CS based voice calls). In addition, due to the integration and combination of VoLTE with RCS based services, subscribers will get a complete solution fulfilling all their communication needs.

What are you most looking forward to about attending the LTE Voice conference?

I am looking forward to exchanging views and best practice sharing with peers across the industry, and to deepen my understanding of the status of LTE Voice.